The present invention relates to a process for treating cacao beans and more particularly, a cacao powder rich in polyphenols, process for the preparation thereof and prepared cacao comprising the same.
A conventional cacao powder has been prepared through steps of crushing washed raw cacao beans to remove a shell and embryo and obtain a cacao nib, treating with an alkali the cacao nib, roasting the cacao nib, grinding the roasted cacao nib, expressing oil, and pulverizing the oil expressed substance.
In general, the alkali and roasting treatments are started with such initial conditions that an amount of water is 10-25% by weight inclusive of moisture in the cacao nib and pH is 6.8-8.0.
The prepared cacao is prepared by adding sugar, powdered milk and the like to the cacao powder prepared as above to adjust its taste, and if necessary, agglomerating the resulting mixed powder. A cacao beverage prepared by dissolving the prepared cacao with hot water has been widely and habitually drunk.
While, the polyphenols are watched substances with great interest, since such reports have been made through recent studies that the compounds have various and biologically favorable functions inclusive of anti-oxidating action, anti-dental caries action, action for preventing arteriosclerosis, inhibiting action of carcinogenesis, anti-stressing action, anti-bacillus and virus actions, anti-allergy action and others.
However, a cacao polyphenol (may be abbreviated hereinafter as xe2x80x9cCMPxe2x80x9d) which is one of polyphenols and contained in the cacao beans shows astringency and bitterness, and thus a cacao powder containing CMP in higher amount can not be said as preferable one from view point of taste. In the conventional process for preparing the cacao powder, therefore, the cacao nib is treated with the alkali to increase solubility and reduce the astringency and bitterness and in other words, the process reduces the amount of CMP originally presenting in the cacao beans. Therefore, there is no measure other than increasing the intaking amount of the cacao beverage or using a prepared cacao which contains the cacao powder in excess amount, is not well-balanced with the sugar and milk and is not preferable from view point of taste, in order to intake the biologically favorable CMP as much as possible by using an adjusted cacao composed the conventional cacao powder.
Basic objects of the invention, therefore, to provide a process for preparing a cacao powder under treating conditions which do not reduce an amount of CMP presenting in cacao beans, as possible, the cacao powder rich in CMP, to be obtained by the process, and a prepared cacao comprising the cacao powder.
Final object of the invention lies in providing a good cacao powder which is not spoiled in taste, in spite of that its CMP content is kept in higher level, to make easy intake of CMP which is excellent in functions.
The inventors have energetically studied and investigated for dissolving said problems and attaining said objects. As a result, they have obtained such findings to establish the invention that preparation of the cacao powder rich in CMP (may be abbreviated hereinafter as xe2x80x9cHPCxe2x80x9d) is possible by adjusting roasting conditions of a cacao nib, and that the astringency and bitterness inherent to CMP can be sharply inhibited by adjusting treating conditions with an alkali, prior to the roasting treatment, in spite of that the cacao powder has relatively high CMP content and although an amount of CMP somewhat reduces than that contained in the cacao beans.
Namely, the invention relates to a process for preparing a cacao powder rich in polyphenols, which is characterized by subjecting a cacao nib to an alkali treatment under water content condition of 3-10% by weight or the cacao nib to a roasting treatment by setting initial water content of 3-10% by weight, without carrying out the alkali treatment, and then carrying out steps of grinding, oil expression and pulverization, in order; the cacao powder obtained by the process; and a prepared cacao composed of the cacao powder.
The basic matter of the process according to the invention lies in that the amount of CMP presenting in the cacao beans does not reduce, as possible, through steps for preparing the cacao powder and thus, it is preferable to use cacao beans in kind and place of production, which contain CMP in higher level, as much as possible, in order to obtain a cacao powder rich in CMP. For instance, the cacao beans produced in Ghana, which have been widely selected for preparing the cacao powder contain CMP of about 3.3% by weight in raw beans, and while the cacao beans produced in Ecuador show higher CMP content of 3.6-6.3% by weight and thus, it is advantageous to use the cacao beans produced in Ecuador, since the amount of CMP is higher than those produced in Ghana. The cacao beans produced in Venezuela can be exemplified as those containing CMP in higher amount, excepting those produced in Ecuador.
In case of carrying out the process according to the invention, taste of finally obtained cacao powder becomes good, if an alkali is added to make final pH to 5.0-7.5 and more preferably to 6.6-7.0, in the alkali treatment. When potassium carbonate, sodium carbonate or the like is used as the alkali, it is preferable to add the same in an amount not exceeding 2.0% by weight to the cacao nib.
It is preferable to set water content in the cacao nib in a reaction vessel for subjecting the cacao nib to the alkali treatment in lower level, as possible, so that CMP presenting in the cacao beans remains in an amount as much as possible. Since moisture contained in the cacao nib per se is 3-7% by weight, in usual cases and thus it is necessary to carry out the treatment under the water content condition of 3-10% by weight, by setting possible adding water of an amount not exceeding 7% by weight.
Further, it is preferable to carry out the alkali treatment under controls of temperature in a range of 50-100xc2x0 C. and stirring time period in a range of 5-30 minutes to finish the reaction under lower temperature condition and shorter period of time, as possible, so as to remain CMP as much as possible.
In the roasting step for carrying out the process according to the invention, it is preferable to set shorter roasting period of time, in order to remain CMP presenting in the cacao beans in maximum level, but it necessary to consider various conditions on an amount of adding water, temperature, roasting period of time and others, in response to kind of the cacao beans for taking out inherent flavor and taste due to the kind of cacao beans. In a usual case, such conditions for the roasting treatment are preferable as standards that initial water content is 3-10% by weight, final temperature of the cacao nib is 120-125 C., and roasting period of time is about 30-50 minutes. For instance, the cacao nib with nice taste can be obtained by if necessary, adding water to make water content of the cacao nib at roast starting time as 10% by weight and then roasting the same for 40 minutes, so as to reach final temperature of the roasted cacao nib to 123 C. (final moisture content of the roasted cacao nib: about 2% by weight), when the cacao beans produced in Ecuador are selected. In case of the cacao beans produced in Ecuador, bright flavor inherent to the beans becomes strong, but grassy-smelling generates, when the final temperature of cacao nib is lower than 123 C., and the flavor becomes poor and taste becomes heavy feeling, when the roasting is carried out until the final temperature of cacao nib exceeds 123 C.
It is preferable that moisture content of the roasted cacao nib is 1-5% by weight and in such a range of moisture content, almost no lowering of CMP content occurs in subsequent grinding and oil expressing steps.
The subsequent step of oil expression from the roasted cacao nib can be carried out in a conventional manner. In the conventional cacao powder, there are two types containing oil as final content of 12-14% by weight and 22-24% by weight, but it is preferable to carry out the oil expression, so that the final oil content becomes 12-14% by weight, to increase CMP content therein. When the process according to the invention is carried out with use of the cacao beans produced in Ecuador, HPC containing CMP of 7-11% by weight can be obtained by carrying out the oil expression, so as to make the final oil extent to 12% by weight. In this case, HPCs containing CMP of 7-9% by weight have proper astringency and bitterness to show nice taste.
When the oil expression is carried out, so as to make final oil extent to 22% by weight, HPCs containing CMP of 6-10% by weight can be obtained.
The prepared cacao can be obtained by composing a saccharoid, powdered milk and edible additive(s) in the HPC and mixing the same or agglomerating mixture in the form of powder in a conventional manner.